We're using redirection to mask links to certain advertisers. WHY? Not to deceive anyone but hide private scripts or create the illusion that the link belongs to this domain. We add "no follow" to these when used in a page to tell search engines not to index the destination and it appears that more urls belong to us instead of going offsite. Truthfully, not everyone will allow this type of modification or their code might not function after processing but has been tested to work with simple forms and still pass data.
What is a hyperlink? The code is simple if you don't add anything fancy: <a href="http://www.insertyourfavorite.com/">link text/image here</a>. Something more elaborate and SEO that can improve your page rank is adding a "title" which describes the destination. This also aids accessibility enabled browsers to offer choices and navigate for their users audibly. Adding that attribute is easy too, it will form like this <a href="http://www.myfirstlink.com/" title="My First Link">My First Link</a>. Keep it Str8!